Multi Landy over 1NT 

dbl    =    penalty

2♣    =    both M (54 versus S1NT, 44 versus W1NT)    ➲

2♦    =    one 6+ card M    ➲

2M   =    5M4+m    ➲

2NT =    both m

3m    =    preemptive

3M    =    6+M, unbalanced, 5LT